Have run the FS series since it's first tenuous incarnation by Microsoft way way back when, with and without the control enhancements you can find today, including the headset vision systems, always found them to be very timid in there approach but as it's all things to all ect I assumed they had to build it that way.
However after a period testing various real life simulators from the Nimrod through to the 737-400 series I realised the limitations were in essence only visual for as an instrument training tool it can be very useful to those about to move onto IMC training.
I know there will be those that doubt this but in reality if you have the will power NOT to look outside or take the time to fiddle with it and disable the exterior scenery and use the instruments alone it has it's good points, taught me a lot about what to ignore and what was important.
But overall it's just a PC game after all and though some of the add-on's are getting very sophisticated, the above mentioned FMC system to name one, you pays your money and takes your choice with FS.